Our Retarded Bonded PC Strand represents an innovative leap in post-tensioning technology, perfectly combining the installation efficiency of unbonded strands with the structural safety and high load-bearing capacity of bonded systems.
The product features a high-tensile 7-wire low relaxation steel strand coated with a specially formulated retarded adhesive paste (retarded mortar), all encased in a durable, ribbed High-Density Polyethylene (HDPE) or Polypropylene (PP) sheath. After installation and tensioning, the adhesive remains fluid for a controlled period (typically 90 to 180 days), allowing free movement of the strand. Over time, the paste cures and hardens inside the ribbed sleeve, creating a permanent, high-strength bond with the surrounding concrete structure without requiring any on-site grouting.
Retarded Bonded PC Strand
Key Product Advantages
Best of Both Worlds: Offers the fast, grout-free, and labor-saving installation of unbonded systems, while achieving the superior structural integrity and crack resistance of bonded systems after curing.
Eliminates On-Site Grouting: No grouting equipment, slurry preparation, or duct-flushing required on the job site. This significantly speeds up the construction cycle, reduces labor costs, and eliminates defects caused by poor grouting quality.
Controllable Curing Time: The advanced retarded adhesive paste is engineered to maintain low friction during transport, handling, and tensioning. Curing triggers precisely according to project requirements.
Excellent Corrosion Resistance: The heavy-duty polymer outer sheath combined with the dense chemical adhesive layer provides dual-barrier protection against moisture and corrosive agents, ensuring a lifespan matching the concrete structure.
Optimized Mechanical Bonding: The outer sleeve is designed with scientifically engineered ribs or deformations, guaranteeing an exceptional mechanical interlock between the cured strand and the concrete matrix.
Typical Applications
Retarded Bonded PC Strands are highly recommended for complex, large-scale engineering projects where high structural safety is required but space or conditions restrict traditional grouting operations:
Large-Span Building Frames: Ideal for post-tensioned (PT) beams and slabs in commercial complexes, convention centers, and high-rise structures requiring clear, expansive open spaces.
Heavy-Duty Industrial Floors: High-load logistics warehouses, aircraft hangars, and manufacturing facilities demanding extreme durability and minimal cracking.
Bridge Infrastructure: Prefabricated concrete bridge girders, viaducts, and cross-sea bridge segments where on-site grouting is logistically difficult.
Special Civil Engineering: Containment vessels for nuclear power plants, LNG storage tanks, rock/soil anchors, and deep foundation reinforcement.
Packaging & Shipping Details
Due to the presence of the retarded adhesive chemical compound, our packaging and logistics processes are strictly managed to maintain temperature stability and prevent premature curing or mechanical damage during sea transit.
Coil Weight: 2.0 to 3.0 Metric Tons per coil (Custom packaging according to lifting capacity at the job site).
Coil Dimensions: Inner Diameter (ID) approx. 750-900mm; Outer Diameter (OD) approx. 1300-1600mm.
Storage & Transit Protection: Wrapped completely in multiple layers of heavy-duty, waterproof woven fabric and UV-resistant plastic film to protect against moisture, sunlight, and salt spray.
Temperature Control: For long-distance sea freight crossing tropical zones, we recommend shipping in climate-controlled environments or scheduling transits to avoid extreme heat, ensuring the retarded paste remains stable.
Container Loading (FCL): Fully optimized for 20ft Containers. Coils are safely secured on reinforced steel or heavy wooden pallets (eye-to-the-sky or eye-to-the-side), firmly choked and strapped with heavy-duty steel bands to prevent any shifting during ocean transport.
Technical Parameters (Specifications)
Our products are manufactured under rigorous quality control and can be tailored to meet international standards such as ASTM A416, EN 10138, or customized project specifications.
|
Parameter |
Standard / Typical Value |
|
Material Structure |
High-Tensile 7-Wire Steel Strand + Retarded Adhesive + Ribbed Plastic Sheath |
|
Common Diameters (Steel) |
12.7mm (0.50"), 15.24mm (0.60"), 17.8mm |
|
Tensile Strength |
1860 MPa (Grade 270) / 1770 MPa |
|
Yield Strength |
≥ 90% of Tensile Strength |
|
Relaxation (1000 hours) |
≤ 2.5% (Low Relaxation) |
|
Sheath Material |
Premium High-Density Polyethylene (HDPE) or PP (Ribbed Profile) |
|
Retardation Period |
90 days / 120 days / 180 days (Customizable based on ambient climate and project needs) |
|
Full Curing Time |
Reaches ultimate bonding strength within 6-12 months post-tensioning |